How to keep track of Translucency and Emission when you setting up lighting
During my time as a Lead VFX Artist, I frequently encountered challenges related to improperly configured lighting setups. Translucent materials would either flare up like a supernova or appear as dark as obsidian, depending on the scene conditions. Similar issues occurred with emissive elements — additive emissive particles would sometimes bloom intensely like a welding arc, while at other times they would disappear entirely. I solved this problem by dividing the emissive into eye adaptation in the master materials of effects.
However, the problem with lit translucency remained unsolved until years later, when I took on the role of Technical Art Director and was finally in a position to directly influence lighting workflows.
In this article, I’d like to share a simple yet effective technique — one that has long existed but is still rarely applied in production.
In Unreal Engine, there's a function that, when you press a hotkey, can display geometry. Its position is determined by the cursor's location on the screen and the geometry behind it. Below is the place where you can bind your test geometry.
By default there is SM_ColorCalibrator. My contribution was creating a Test Chart that includes emissive and translucency, and demonstrating how it works to the lighting artists.
What you need to understand if you create your own table:
Gamma Correction
sRGB is a color space with a gamma curve designed to mimic how the human eye perceives light. Optimized for display on monitors and devices to make images look "natural" without requiring high bit depths.
Gamma Encoding sRGB applies a non-linear gamma correction (approx. γ≈2.2\gamma ), meaning it compresses the range of light intensity values, dedicating more detail to darker tones (where the eye is more sensitive).
Linear Color it Is: A color space where the values are directly proportional to the light intensity, without gamma correction.
Why avoid pure black and pure white during production?
1. Preserving dynamic rangeIf you crush the blacks to 0 or clip the whites to 255 (in 8-bit terms), you lose detail in shadows and highlights. A soft contrast keeps more subtle variations.
2. Flexibility in color grading
A flat, low-contrast image gives the colorist more control. They can later push the image to any look — cinematic, stylized, realistic, moody, etc.
If the contrast is already baked in, the image is harder to adjust without causing artifacts or banding.
3. Avoiding clipping
Pure white and pure black are dead zones — there’s no information left to adjust. That means if something is blown out, you can’t recover it.